We have heard and read before that our Imam (atfs) is perhaps living in Jaziratul Khadra.

Jaziratul Khadra is often linked to the Bermuda Triangle.

For example:

During this time he continues to guide. Numerous letters have been received from him by (to quote a few) Ishaq bin Yaqub, Sheikh Mufeed.... It is reported that 30 people all over the world meet with him regularly. It is also reported that Jaziratul Khadra (green islands or Bermuda Triangle) is a vast land in Imam's kingdom occupied by a large number of Shia and governed by Imam's family. http://www.ziaraat.com/sammeh01.php